Wayland and X11 (also known as the X Window System) are two different display server protocols used to manage graphical interfaces in Linux and Unix-like operating systems. Their main differences lie in design philosophy, architecture, and performance. Here are the key distinctions:1. Design Philosophy and ArchitectureX11: Historical Background:X11 has been the standard display server protocol used in Linux and Unix-like systems since the late 1980s.Client-Server Architecture:X11 employs a client-server architecture where the client is responsible for rendering graphics, while the X server manages the display of the screen, input devices (such as keyboard and mouse), and windows. Complexity: X11 is a very flexible and powerful protocol, but it is also quite complex, containing many outdated and redundant features that can lead to performance issues and security vulnerabilities. Network Support: X11 allows for remote display, enabling applications to run on one machine while displaying graphics on another.Wayland: Modern Design: Wayland is a modern protocol designed to simplify the graphics stack and improve performance. Its goal is to replace X11 and provide a more efficient and streamlined display server protocol. Direct Rendering: Wayland adopts a simpler and more intuitive design, where the window manager interacts directly with the display hardware, reducing the complexity of intermediary layers. Client applications render their graphics output directly to the screen without relying on an intermediary server. Simplified Communication: Wayland does not have as many features as X11, removing a lot of legacy complexities, making it lighter, more modern, and easier to maintain.2. Performance and EfficiencyX11:Due to its long history, X11 employs many redundant mechanisms, resulting in lower efficiency. Especially in high-performance graphics rendering and animations, X11’s performance often lags behind that of Wayland. Resource Consumption: X11 requires more computational resources to manage window management, input device management, and graphics rendering coordination.Wayland: Wayland offers superior performance as it reduces redundant intermediary layers, directly handling graphics rendering and minimizing latency. Hardware Acceleration: Wayland fully utilizes hardware acceleration, avoiding the intermediary conversion processes found in X11, making graphics rendering more efficient.3. Compatibility and SupportX11: Strong Compatibility: X11 supports almost all graphics drivers, applications, and tools, making it the most widely used display server protocol on Linux. Many older applications still rely on X11. Remote Display: A significant feature of X11 is its support for remote display. You can run a graphical application on a remote machine and display its output on a local machine.Wayland: Limited Compatibility: Wayland has not yet fully replaced X11, so some older applications and graphics drivers may not be fully compatible with Wayland. Weaker Remote Display Support: Wayland does not natively support remote display features like X11. Although there are some protocols and tools (such as XWayland) that can accommodate X11 applications, their functionality and performance are generally not as good as running directly on X11.4. SecurityX11: Security Issues: X11 has poor security, especially in multi-user environments. Since X11 allows client applications to interact directly with other applications, this can lead to security vulnerabilities. Permission Management: X11 lacks robust permission management mechanisms, allowing any application with access to the X server to access the graphical output of all other applications.Wayland: Higher Security: Wayland places greater emphasis on security in its design, limiting direct interactions between applications. Each application can only access the rendering content of its own window and cannot access the graphical output of other applications, thereby reducing potential security risks.5. Current SupportX11: X11 is a mature protocol, fully supported by almost all Linux distributions, desktop environments (such as GNOME, KDE), and graphical applications.Wayland:Wayland’s support is gradually increasing, especially in new desktop environments and distributions (such as GNOME, KDE Plasma, and Ubuntu 21.04+). However, Wayland may encounter compatibility issues on some older hardware or software. XWayland: To accommodate X11 applications, Wayland has introduced the XWayland layer, which allows X11 applications to run on Wayland, but performance and compatibility may not be as good as running directly on X11.6. Desktop Environment and Window Manager SupportX11: X11 serves as the foundation for many desktop environments (such as GNOME, KDE, XFCE) and window managers, with almost all Linux desktop environments based on X11.Wayland: Currently, Wayland has good support in some desktop environments (such as GNOME and KDE Plasma). In particular, GNOME performs exceptionally well when running on Wayland. However, some window managers (such as i3, Openbox) do not yet natively support Wayland, requiring additional tools or solutions (such as Sway as a Wayland-compatible version of i3).ConclusionX11: As a traditional display server protocol, it offers broad compatibility and remote display capabilities but suffers from lower performance and security issues.Wayland: As a modern alternative, it provides higher performance, stronger security, and a simplified design, but its compatibility and support have not yet reached the level of X11.As Wayland matures, it is expected to gradually replace X11, especially where significant advantages in performance and security are evident. However, for now, X11 remains the standard graphical protocol for most Linux systems.